Corrugated panel making machine and method



Oct. 23, 1962 W.4D. BEHLEN 3,059,685

CORRUGATED PANEL MAKING MACHINE AND METHOD Oct. 23, 1962 Filed Sept. 9, 1957 as IO/ 8G 5 Sheets-Sheet 2 Oct. 23, 1962 w. D. BEHLEN CORRUGATED PANEL MAKING MACHINE AND METHOD 5 Sheets-Sheet 3 Filed Sept. 9, 1957 W. D. BEHLEN CORRUGATED PANEL MAKING MACHINE AND METHOD Oct. 23, 1962 5 Sheets-Sheet 4 Filed Sept. 9, 1957 fijVENTOR.

Oct. 23, 1962 w. D. BEHLEN 3,059,685

CORRUGATED PANEL MAKING MACHINE AND METHOD Filed Sept. 9, 1957 s Sheets-Sheet 5 INVENTOR.

BY ii 3,059,685 CORRUGATED PANEL MAKING MACHINE AND METHOD Walter D. Behlen, Behlen Mfg. Co., Columbus, Nebr- Filed Sept. 9, 1957, Ser. No. 682,901 1 Claim. (Cl. 153-77) This invention relates to a machine for the manufacture of corrugated sheet metal panels which are curved lengthwise and which are of sufficiently light gauge as to be economically practical when used in prefabricated metal buildings.

A particular object is to provide a machine and method for forming panels of this type which are of a lighter gauge material than it has been heretofore thought could be made without a buckling of the material transversely of the corrugations.

In the Standard Materials Handbook, Light Gauge Steel Design Manual of the American Iron and Steel Institute, used throughout the industry it is stated that light gauge sheet meal compression members, as seen in cross section, should have no flat areas of a width of more than a certain number of times the thickness of the material itself as an upper limit without buckling occurring during stressing of the material in compression beyond its elastic limit. As the elastic limit of a deeply corrugated panel must be exceeded in lengthwise curving of the panel, construction of such light gauge panels without transverse buckling has been an industry-wide accepted impossiblity.

The prior art view.-The elastic limit of the compression portion of a conventional deeply corrugated light gauge panel must be exceeded in lengthwise arching of the panel; therefore transverse failures or crosswise buckles will inevitably occur. Therefore construction of arched, economically light-gauge panels of suflicient corrugation-depth for practical building-roof strength, without failure by transverse buckling, has been an industry-wide accepted impossibility.

So much is this an accepted impossibility that one prior art building has arched panels made with transverse corrugations or buckles purposely added to permit lengthwise arching. However such purposely added corrugations or buckles weaken the panel just as much as the unwanted buckles whereby the material of such a panel must be of a very heavy gauge or of unnecessarily great depth of corrugation to provide a desired strength, as defeats economy.

My new cncept.-I have discovered a way of making a machine with which it is possible to curve light sheet metalsufiiciently light for practical economy in competition with other ways of construction when used in prefabricated steel bui1dingsin the construction of arched corrugated panels: (a) without transverse buckling or corrugation, and (b) at the same time achieving the limiting of any substantially flat portions of the panels, as seen in cross-section, to widths which are narrow enough to conform to strength rules similar to the above handbook rule. My Way of making a machine for this purpose has never before been done and it achieves results heretofore thought impossible.

I am aware that others have produced arched corrugated panels. However such machines have always been different in many respects. Certain of these earlier machines are:

The French patent to Heineman, Patent No. 867,064, issued June 30, 1941, and the American patent to Romanoff, Patent 2,163,063, issued June 20, 1939, entitled =Machine for Making Corrugated Articles.

In neither of these machines is there an attempt to make a panel which is double-corrugated; in other words,

ice

with smaller lengthwise corrugations Within larger lengthwise corrugations. The panels made in such machines were not arched whereby the problem presented in making an arched, double-corrugated, light-gauge panel was not presented.

Certain other patents have shown pre-forming rolls precedent to final forming rolls. In these patents the preforming rolls gradually increased the corrugation and the final forming rolls were rather a gradual increase in the sharpness of corrugation bending compared to the last stage of pre-forming. However I have discovered that the making of a light-gauge arched panel involves the need for double corrugations and great corrugation depth and I have discovered that this can best be done by providing final forming rollers which put the small lengthwise corrugations in the large lengthwise corrugations in one step, no attempt at small corrugations within large lengthwise corrugations being done in the pre-forming stages. A machine of this description has never before been made.

A particular objective is to provide, in such a machin a two-stage bending done by a first deflector means adjacent the final stage rollers and a second deflector means spaced a greater distance from the final stage rollers than the first deflector means is spaced therefrom to achieve a bending desired.

Yet other important objectives are in the provision of guide track and track follower means adapted to engage a worksheet at its center whereby guiding at the edges is not depended on as it was in certain prior art machines whereby shrinkage from corrugation does not disrupt alignment.

Further objects are to provide feed or drive rollers, close to the center of the sheet, preferably sustantially as close together as possible, so that the firm gripping of drive rollers tends to assist alignment, permitting free corrugation bending and shrinkage of lateral width during corrugation preforming stages.

Another objective is to provide a machine having many pre-forming rollers in excess of a dozen in a row and preferably side-by-side and so very closely spaced as to be substantially continuous from entrance end of the preforming section to the exit end.

Other and further objects and advantages of the present invention will be apparent from the following detailed description, drawings and claim, the scope of the invention not being limited to the drawings themselves as the drawings are only for the purpose of illustrating a -way in which the principles of this invention can be applied.

Other embodiments of the invention utilizing the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claim.

In the drawings:

FIG. 1 is a top plan view of the machine, with certain parts broken away;

FIG. 2 is an end elevation of the machine as seen from the left end in FIG. 1;

FIG. 3 is a detail of the exit end of the machine as seen in side elevation;

FIG. 4 is a right end elevation of the entrance into the machine as seen from the right end in FIG. 1;

FIG. 5 is a detail showing two feed roller shafts and their driving gears and certain associated parts;

FIG. 6 is a view-in-section taken along the line 66 of FIG. 5;

FIG. 7 is a view taken in cross-section through a corrugated curved sheet metal panel of the type made by this machine;

FIG. 8 is an elevation of one of the final corrugation 3 rollers of the machine, a portion of which is broken away for further illustration;

FIG. 9 is a view of the exit or left end of the machine as it is shown in FIG. 1 and as seen in vertical section;

FIG. 10 is a view of the machine as seen along a vertical plane extending forwardly and rearwardly through the center of the machine, certain parts not being shown for clarity of illustration; and

FIG. 11 is a side elevation of the machine as it is seen with the cover portion removed, certain parts not being shown for clarity in illustrating the feed roller assembly,

FIG. 12 is a vertical cross sectional view taken along the line 12-12 of FIGURE 1, showing a sheet of material supported on the sheet supporting members; and

FIG. 13 is an enlarged fragmentary detail of one end of a sheet of material showing the siding material centering key and keyway and its disposition in use.

The machine for forming building panels of this im vention has a frame generally indicated at 10.

The frame 10 is elongated and has an entrance end at the right, as best seen in FIG. 1, and an exit end at the left. At the entrance end, the frame 10 has suitable horizontally disposed members 12 which are arranged in a horizontal plane for supporting a flat sheet of material 14, as best seen in FIG. 9, as the material is manually moved forwardly on the machine in the direction of the arrow 18.

When the forward edge of the fiat sheet of material is inserted between upper and lower feed rollers 20, the feed rollers pull the sheet of material forwardly. The feed rollers 26 are arranged in two groups, a first group being disposed above the pathway of the sheet 14 and the second group being disposed beneath the pathway of the sheet. As best seen in FIG. 4, the rollers of the upper group are disposed closely spaced with respect to the rollers of the lower group and preferably the rollers of the upper and lower groups are pressed toward each other with considerable force by means which will now be described.

The rollers of the upper group are arranged on horizontal shafts 24 which latter are each suitably received in a bearing '26, best seen in FIGURE 6.

The bearings 26 can be maintained in position on shafts 24 by suitable snap rings 28 fitting in grooves in the shaft shown.

The bearings 26 are prevented from moving out of place forwardly and rearwardly by suitable retaining members 30 which extend vertically, FIGURE 6, and which are interconnected by horizontal members 32 and bolts or the like 34 at the upper ends of the members 30. The lower ends of the members 30 can be suitably maintained in position by attachment to members 36 which latter are horizontal members of the frame 10.

Other horizontal members 40 and 42, FIGURE 5, of the frame 10 are shown in FIGURE 5 and 6 and these hold the upright retaining members 30 in place, being suitably secured thereto.

Vertical adjustment bolts are threadedly mounted, FIGURE 5, through the horizontal members 32 and through the frame member 36 respectively, whereby the adjustment screws 50 are adapted to press the upper bearings 26 downwardly and the lower bearings 26 upwardly for forcing the shafts 24 toward each other, preferably with suificient force that the shafts actually bend under the force for pressing the feed rollers 20 of the upper group against the feed rollers 24) of the lower group with such force as to firmly grip the sheet of metal 14 which is passing through the machine.

The feed rollers 20 of the upper group, FIGURE 4, are preferably arranged in two rows which are spaced only a short distance apart, each row being an equal distance from the center of the respective shaft 24. Each shaft 24 of the upper group of shafts is disposed directly above shaft '24 of the lower group whereby the feed rollers on the lower shaft are each also disposed in two rows lengthwise of the machine and are spaced apart a short distance from the longitudinal center of the machine and directly beneath respective rollers of the upper group of rollers 20.

As best seen in FIGURE 4, an endmost one of the shafts 24 of the lower group, and which is best seen at 54, can be of lesser length than other feed roller shafts and can terminate at the center as shown in a bearing assembly 56 mounted on a suitable frame member 58.

As best seen in FIGURE 10, the sheet of material 14 passes from the outer supporting frame members 12 into the remainder of the machine and enters what I call a corrugation preliminary forming stage. I have a first group of corrugation preliminary forming means or assemblies disposed above the sheet as it enters this stage and this means preferably comprises one or more elongated channel members 60, FIGURE l0, which are disposed extending substantially horizontally but inclined slightly as later described. The channel members 60 are each supported by suspension on bolts 62 which latter are supported from transverse horizontal frame members 64 which are disposed above the feed rollers 20 at spaced apart points along the length of the channels 60.

The upper channels 60 incline downwardly as they approach the exit end of the preliminary forming stage of the machine. A second group of preliminary forming means or assemblies is provided which is preferably in the form of lower channels which are open on their upper sides and which are elongated, substantially horizontal, and which are inclinedly disposed with respect to the upper channels 60, or in another sense the two groups of channels 60 and 70 are inclinedly disposed with respect to each other whereby they tend to cross at a point between their ends as seen in side elevation in FIGURE 10.

On the under side of the upper channels 60 and on the upper side of the under channels 70 rows of closely spaced apart rollers 72 are arranged, each supported on a substantially horizontal pin 74 whereby the rollers are free to rotate to provide a minimum of resistance as a sheet of metal passes therethrough.

The rollers of the upper and lower groups are spaced apart a distance at least as great and preferably greater than the thickness of a sheet of metal whereby the sheet of metal can be freely received between the upper and lower groups of rollers 72 at the entrance end of the preliminary corrugation stage.

In this way the rollers 72 of the first and second groups of elongated channels 60 and 70 form surfaces for contacting the sheet of metal passing therethrough which are arranged substantially along straight lines respectively, the straight lines of the first group being crossed, as seen in side elevation, with the lines of the second group.

As best seen in FIGURE 4, the channels 60 of the elongated forming means of the first or upper group are laterally spaced apart with respect to each other and the channels and rollers 70 and 72 of the elongated forming means of the second and lower group are laterally spaced apart with respect to each other and are also staggered laterally with respect to the channels 60 of the first or upper group of elongated corrugation preliminary forming assemblies.

At each of the outermost sides of the preliminary corrugation assembly defined by the rollers 72 and associated parts are elongated upper and lower guide members 86 and 88 arranged in pairs, one pair on each side, with the members of a pair having opposed surfaces which are curved as seen in cross section.

The upper and lower guide members 86 and 88 on one side are attached to the frame; the upper members 86 being depended from the horizontal frame members 64 by elongated vertically disposed bolts 89 which latter have their lower ends suitably fixed to the guide 86. The lower members 88 are supported on upwardly extending brackets 91 which latter are suitably secured to horizontal frame cross bars 93 disposed transverselyof the frame and below the preliminary corrugation forming assemblies.

The upper and lower guide members on one side are attached to the frame and are disposed in alignment with each other and are inclined inwardly toward the center of the machine as the exit end of the preliminary corrugation stage is approached, as best seen in FIGURE 1, and serve to prevent the sides of the panel from moving upwardly and downwardly.

As best seen in FIGURE 1 the forming assemblies of the upper or first group and the lower or second group which are disposed on one side of the machine converge with respect to the assemblies on the other side of the machine respectively for the gathering of the material of the sheet inwardly, as it progresses through the machine, and into preliminary corrugations.

Although it is difiicult to see on the scale shown in FIG- URE l, the outermost forming assemblies are arranged on lines more inclinedly disposed with respect to a straight line down the center of the machine than forming assemblies which are arranged closer to the center of the machine.

As thus described, the flat sheet of material 14 is changed into a corrugated piece of material as it passes through the preliminary corrugation stages of the machine, the elongated preliminary corrugation assemblies gradually pressing corrugations into the machine and also gath ering the material inwardly as the material progresses through the machine whereby as it leaves the exit end of the preliminary forming assemblies 60 and 70 the sheet is of lesser lateral width than when it enters the machine.

However it is very important to recognize that the material as it leaves the preliminary corrugation assemblies is not completely corrugated in the form shown in FIG- URE 7 but only has a preliminary form in which the corrugations are of a much lesser angularity with respect to adjacent parts of the sheet than the corrugations of the finished product.

The feed rollers 20 are each driven by a chain 90 extending around the gears 92, each of which latter is mounted at the right end of the respective feed roller shafts 24, as best seen in FIGURES 4 and 11. Idler gears 94 are disposed above horizontal portions of the chain drive 90 to assure driving contact of the chain 90 with the gears 92.

The chain 90 extends over a driving gear 98 which latter is mounted on a shaft 100 extending outwardly from the frame of the machine adjacent a final corrugation forming stage of the machine, later to be described.

Elongated vertically disposed protective shields '95 are disposed on each side of the machine which cover the protruding gears 92 and chain drive 90 and also the shaft ends on the opposite side of the frame.

The shields 95 are removably mounted in shield mounting brackets 97 which are attached to and extend a substantial distance outwardly from the frame sides at the top and bottom thereof. Spacer members 99 attach the brackets in position. The shield mounting brackets 97 are provided with elongated trackways 1 adapted to receive the upper and lower edges of the shields 95 therein allowing slidable engagement therewith.

Referring to FIGURES 2 and 3, at each side of the exit end of the machine and at the bottom are two motors 120 which have pulleys 1122 carrying belts .124 driving larger pulleys 126 which latter are disposed one on each side of the machine.

The larger pulleys 126 each are mounted on a shaft 128 which extends into a gear housing 130 or 132.

The gear housing 130 extends upwardly to and drives a horizontally extending upper roller assembly 136 which has a shaft 138 rotatably mounted in bearings 140, suitably fixed to upright frame members 142.

The shaft 138 has outer ends 144 which are cylindrical in shape and which are received in the bearings 140. The upper roller assembly 136 forms the first means of *6 a first and second cooperative final corrugation forming means, the second final corrugation forming means being a second and lower roller assembly 150 preferably disposed directly beneath the first roller assembly 136.

The first and second shafts 138 and 152 of the first and second roller assemblies 136 and 150 each preferably have circumferential indentations therein, as best seen at 154 in FIGURE 8, the indentations 154 being preferably disposed in pairs, each pair being spaced apart a considerable distance from the other pairs along the respective roller. The indentations 154 of a pair are themselves spaced apart and the surface of the roller extends outwardly in annular surfaces of convexial curvature, best seen at 156, between the indentations 154.

On each side of the indentations 154 of each pair of the surface of the respective roller inclines outwardly in further annular surface portions 158 of convex curvature to substantially the outer diameter of the shaft as defined by the end portions 144 thereof, the further convexial surface portions 158 join the otherwise substantially cylindrical outer surface of the respective shafts 138 and 152.

The purpose of the roller shape described can be best understood by a study of FIGURE 7 in which is shown a portion of the panel 14 made by the machine and in which it is seen that the panel 14 has many large lengthwise corrugations or waves 172 as seen in cross-section. It can be seen that any number of waves of large corrugations 172 can be disposed between the side edges 174 of the panel.

The panel 14 has side edges 174 which are preferably left uncorrugated to overlap and be bolted to similar uncorrugated edge portions of other panels, not shown, in the formation of a roof or wall structure.

Between the edge portions 174, FIGURE 7, are three full large corrugations 172 on one side and two full corrugations 172 and two half large corrugations 176 on the other side. Each of the large corrugations 172 has within it many small lengthwise corrugations or vertical creases 176 for greater strength. The more vertical creases 176 are used proportional to each larger corrugation 172, the greater strength the panel has.

The material between each pair of adjacent vertical small corrugations 176 can also be called a small corrugation 178 if desired because these surface portions or small corrugations 178 are preferably concave on one side of the panel and convex on the other, being convex on the sides that face the neutral axis 180 of the panel.

The panel further has other portions disposed partially on each side of the neutral axis 180 which can be called web portions 184. The Web portions in the panel of FIGURE 7 are straight, as shown.

A comparison of the cross-section of the panel of FIGURE 7 with the exterior shape of the roller assembly of FIGURE 8 will show that the two are complemental It is in this same way that the upper and lower roller assemblies 136 and are complemental and inter-fitting with respect to each other.

Referring to FIG. 8 it will be seen that the first and upper final corrugation roller assembly 136 further comprises annular members 200 which are approximately circular as seen from the end of the shaft 138 and which are rotatably mounted around the shaft 138 and which are spaced apart along the axle 138 various distances corresponding to the spacing of the large corrugations 172 along one side of the panel 14, FIGURE 7.

The annular members 200 are each rotatably mounted on the axle 138 preferably by means of roller bearings 210. The annular members 200 are adapted to form the small corrugations which are the indentations or creases 176 and the arcuate surfaces 178- and for this purpose the members 200 each have concave surfaces 220 spaced apart between outwardly extending annular ridges 222 which latter form the creases or indentations 176' of the panel 14.

Annular web-forming members which are approximately circular as seen from the end of the shaft 138 are provided. The web-forming annular members 230 are each of progressively larger diameter the farther they are from the respective small corrugation forming member 200. Each annular member 200 and 230 has flat sidewalls extending in vertical planes transverse to the axle 138 and each web-forming annular member 230 is mounted on the axle 138 by suitable bearings such as ball bearings 240.

The web-forming members 230 are disposed in groups, each group being on one side of a respective small corrugation forming annular member 200. The web-forming annular members 230 of a group have inclined outer surfaces ext-ending at an angle with respect to the axis of a shaft 138 similar to that defined between the web 184 and the neutral axis 180 of the panel 14.

The details of inner construction of the lower final corrugation roller assembly 150, FIGURE 9, are not shown because they are identical to that of the upper roller assembly 136 with the exception that all portions making up the external surfaces of the lower roller assembly 150 are staggered in relationship to similar surfaces on the upper roller assembly 136.

As best seen in FIG. 9, the sheet of material 14 becomes finally corrugated as it passes between the roller assemblies 136 and 150.

On the exit side of the roller assemblies 136 and 150 is a deflector assembly 270 which has a deflecting member 272 having an upper surface which is preferably corrugated into a shape similar to the upper contour of the lower roller 150 as seen in an end view of the machine and complemental to the shape of the sheet of metal 14.

The deflecting member 270 is preferably formed of a sheet of metal which is held in place by an adjustment assembly comprising crank screws 274 rotatably received in blocks 276 which are attached to and support the deflector member 272. The crank screws 274 are in threaded engagement with mounting members 280 which are respectively attached to the frame of the machine at each side of the machine.

As thus described the deflector 272 can be positioned for forcing the sheet metal member 14 upwardly and cause it to have the arcuate shape shown in FIG. 9. For this reason the entrance side of the deflector 272 is lower than the exit side thereof.

The machine further has a panel weight supporting assembly 280' which comprises preferably a panel engaging roller 282 mounted on an axle 284 supported in bearings 285 upheld by and adapted to travel between upright frame members 290 of the machine being ad justably positioned by an adjustment assembly 292 mounted on the frame of the machine and connected to the bearings 285.

The roller 282 is preferably disposed a suflicient distance upwardly from the deflector member 272 so that the roller 282 gives support to the panel.

As best seen in FIGURE 12, the machine has a horizontal trackway 300 carried by spaced supports 302 of the frame 10 to which latter the trackway 300 is adjustably connected by means of a member 304 adjustably secured by bolts 305 in vertical slots 305 of the support 302 for vertical adjustment of the trackway.

The trackway 300 extends completely through the machine from the entrance end to the final corrugation rollers and lies in the longitudinal center of the machine.

Track followers 306 are arranged one at the forward and one at the rearward end of the sheet 14 each follower 306 having a shank and a head, the head being slidably received in the trackway 300.

The final corrugation roller assemblies 136 and 150, FIGURE 2, each have notches 310 respectively for allowing the shank and head respectively of the follower to pass therethrough. It is particularly important that the corrugations formed in the sheet between first and second final corrugation forming roller assemblies are of greater, or in other words are bent more sharply, with respect to adjacent areas of the sheet of metal than the corrugations formed by the preliminary corrugation forming stage.

It will be seen that the deflector assembly 270 could be a roller, if desired.

A further trackway 300 is disposed at the exit side of the final corrugation forming roller assemblies 136 and 150. The trackway 300' serves to retain the track followers 306 as they pass through the roller assemblies 136 and 150 and the panel is forced upwardly by the deflector 272. Thus the track followers 306 are deposited in the trackway 300 whereby they may be removed therefrom, after the formed panel has left the machine, and returned to the entrance end of the machine by the operator for use with a succeeding sheet of material.

It is important to realize that the corrugations in the sheet become progressively more fully bent as the exit end of the preliminary corrugation forming stage is approached and that the corrugations in the preliminary corrugation stage become more closely spaced apart from one another and of progressively greater depth, and yet are blunt and not sharply corrugated as the exit end of the preliminary corrugation stage is approached. The corrugations of the shaping surface of the machine in the final corrugation forming stage are bent far more sharply than the blunt corrugations of the pathway of the sheet at the exit end of the preliminary corrugation forming stage.

As thus described, it will be seen that the sheet 14 follows through the machine being first gathered inwardly and corrugated in preliminary corrugations, then finally corrugated in definite corrugations, then bent into a curve.

Without these stages, continuous formation of all corrugations simultaneously is impossible. For example, if any of the preliminary corrugations were bends of the same sharpness of angle as the final corrugations, then alignment problems will result and a product of unsightly appearance results.

Likewise, if corrugations of only the preliminary kind were used before bending, then the bending would produce transverse buckles of the kind it is an object of this invention to avoid, unless the corrugations are made of very little width.

To gain suflicient strength the corrugations must be deep and conserve material for economy. The corrugations must be wide for otherwise the web portions, which are relatively useless from the standpoint of providing strength to resist bending, consume the major part of the material and economy is lost.

From the foregoing description, it is thought to be obvious that a machine for forming building panels constructed in accordance with my invention is particularly well adapted for use, by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof, and for this reason I do not wish to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice, except as claimed.

I claim:

In a corrugated panel forming machine, the combination which comprises: an elongated frame, a plurality of laterally spaced rows of upper and lower rollers, the upper rollers having undersurfaces disposed in a first plane, the lower rollers having upper surfaces disposed in a second plane, said first plane being spaced above said second plane at an entrance end of the machine to receive said sheet metal, said planes intersecting in a mid-portion of said machine, said rollers being disposed in laterally spaced longitudinal rows which are equidistantly spaced apart at all points along said machine, said rows converging toward each other toward the exit end of said preforming section, and said first plane being disposed below said second plane at the exit end of said preforming section for causing said sheet to be corrugated, and coacting finishing rollers at the exit end of the frame, the

finishing rollers being in meshing relation and having al- 5 ternate large and small diametered portions, the large diameter portions having annular concave surfaces therein disposed side-by-side and spaced apart by annular ridges, said small diametered portions having annular convex surfaces therein spaced apart by annular sharply concave furrows, the coacting finishing rollers intermeshing to thereby form arcuate ribs on the corrugated sheet feed from the rows of rollers.

References Cited in the file of this patent UNITED STATES PATENTS Montgomery Apr. 12, 1859 Kane May 10, 1910 Johnson Sept. 27, 1910 Hunker May 10, 1921 Watkins Sept. 15, 1931 Sneed Dec. 12, 1933 Ruegenberg July 26, 1938 Romanott June 20, 1939 Loggins July 11, 1939 Fay Aug. 25, 1953 FOREIGN PATENTS France June 30, 1941 

